Treatment of casein.



UNITED STATES Patented May 10, 1904.

PATENT OFFICE.

TREATMENT OF CASEIN.

SPECIFICATION forming part of Letters Patent No. 759,808, dated May 10,1904.

Application file'l September 24, 1903.

To all whom lit 777,611 71 concern.-

Be it known that I, LOUIS A. DREYFUS, a citizen of the United States,and a resident of New Brighton, in the county of Richmond and State ofNew York, have invented certain new and useful Improvements in theTreatment of Casein, of which the following is a speciiication.

My invention relates to the treatment of casein, the object being mainlyto improve its insoluble properties when used as one of the componentparts of paint or for other purposes.

In the use of ordinary casein as one of the component parts of paint ithas been found to have two rcactions that is to say, when mixed withlime or other solvents, as in making paint, a compound is formed whichis soluble in water. The second reaction is that in time the compoundbecomes insoluble in water; but with the common casein paint, commonlyknown as cold-water paint, a considerable time is required for thesecond reaction to become fixed. With my treatment the second reactionbegins almost immediately and is practically complete within abouttwenty-four hours, so that while with ordinary casein-paint wetting ofthe painted surface, as by rain or snow, will cause the paint to washoff with my method the insoluble condition is practically completewithin a comparatively short time and wetting of the painted surfacewill have no material effect.

In carrying out my process I take dry casein, which contains sulfuric orother acids, either added to the product or left therein in the processof making it from the milk, and subject it to the action of heat andcontinue the heating for a protracted period of time, varying with thetemperature employed. I have found that a temperature slightly below theboiling-point of water continued for about twenty-four hours willdehydrate or change the properties of the casein so that while itssoluble qualities when mixed with lime or other solvent and water willremain about the same, yet after such mixture the secondary reactionwill immediately begin, and within about twenty-four hours after appli-Serial No. 174,443. (No specimens.)

cation the paint will be practically insoluble and weatherproof.

While the temperature and the period of time of heating mentioned-towit, say about 200 Fahrenheit above zero continued for about twenty-fourhours-are preferred, I have found that a temperature of 120 Fahrenheitabove zero continued for one hundred hours will produce a desirableresult, and therefore I do not wish to be understood as limiting myselfto any special temperature or to any special period.

Another step in my process consists in mingling talc, whiting, or otherpulverized base with the dry acidulated casein and subjecting the wholeto heat, as before. The main advantage of this is that the tale,whiting, or other neutral base serves to insulate or protect to a degreethe casein from the dangers of excessive heat and from being scorched,and in this way a higher temperature may be safely employed, thusreducing the period of continuing the treatment.

Having thus. described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The process herein described of improving the insoluble properties ofcasein which consists in subjecting it while in a dry state to theaction of heat in the presence of acid, substantially as set forth.

2. The process herein described of improving the insoluble properties ofcasein which consists in subjecting it while in a dry state to theaction of heat in the presence of sulfuric acid, substantially as setforth.

3. The process herein described of improving the insoluble properties ofcasein which consists in heating acidulatcd casein mixed with a mineralbase substantially as set forth.

4. The process herein described of improving the insoluble properties ofcasein which consists in subjecting dry acidulated casein to the actionof heat for a period of twentyfour hours more or less, substantially asset forth.

LOUIS A. DREYFUS.

W itnesscs:

H. A. EST, JACOB MAKAY.

